Modeling carbon fluxes in tidal forested wetlands in the Mississippi river deltaic plain under various hydrologic conditions: implications for river diversions

Authors

Hongqing Wang, United States Geological Survey
Ken W. Krauss, Louisiana Universities Marine Consortium
Gary P. Shaffer, Southeastern Louisiana University
Brett A. Patton, United States Geological Survey
Daniel E. Kroes, United States Geological Survey
Gregory B. Noe, United States Geological Survey
Zhaohua Dai, Michigan Technological UniversityFollow
Lindsey Dettwiller, Southeastern Louisiana University
Carl C. Trettin, USDA Forest Service

Document Type

Article

Publication Date

2-1-2026

Department

College of Forest Resources and Environmental Science

Abstract

Our understanding of the impacts of climate change, sea-level rise (SLR), and freshwater management on the magnitude and variability of carbon fluxes in tidal forested wetlands remains limited. In this study, we applied a process-driven wetland biogeochemistry model, Wetland Carbon Assessment Tool—DeNitrification-DeComposition (WCAT-DNDC) model to explore responses of carbon fluxes in tidal swamp forests to climate change-induced alterations in hydrologic conditions and to predict impacts of planned reintroduction of river flows. We selected twelve sites in three habitats (throughput, relict, degraded) inside the Lake Maurepas swamp forests (Louisiana, USA) to represent various hydrological and salinity regimes. Environmental scenarios included dry, average, and wet conditions, SLR (low and high), and a Mississippi River (MR) diversion. Simulation results showed that the responses of net ecosystem exchange (NEE), net primary productivity (NPP), ecosystem respiration (ER), methane (CH4) and nitrous oxide (N2O) emissions in the Lake Maurepas swamp forests varied substantially among sites. However, the overall net carbon uptake capacity of the Lake Maurepas swamp forests was high (NEE: − 1143 to − 1650 g C m⁻² yr⁻¹), suggesting that Lake Maurepas swamp forests are large carbon sinks. The high net carbon uptake capacity could be significantly affected by climate change induced drought, flooding, and SLR with the bi-directional changes (increase or decrease) depending on the direction and magnitude of the hydrologic regime changes. The response of the net carbon uptake capacity to MR diversion is also bi-directional and site-specific, but enhancement of the capacity of NEE of up to − 1957 g C m² yr⁻¹ is possible, implying that MR diversion into the swamp forests could be beneficial in the context of carbon cycling and carbon sequestration.

Publisher's Statement

This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2026.

Publication Title

Wetlands Ecology and Management

Recommended Citation

Wang, H., Krauss, K., Shaffer, G., Patton, B., Kroes, D., Noe, G., Dai, Z., Dettwiller, L., & Trettin, C. (2026). Modeling carbon fluxes in tidal forested wetlands in the Mississippi river deltaic plain under various hydrologic conditions: implications for river diversions. Wetlands Ecology and Management, 34(1). http://doi.org/10.1007/s11273-026-10111-5
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/2309

Version

Publisher's PDF